Alternate options for the MAC filter list, which has a limit of 256 entries

We have a customer on Hivemanager that has used close to their limit of 256 MAC addresses. There is no way through the gui to extend this from what I can see so far. The customer already uses .1x authentication as well, however still wants to limit access by devices (they are aware that this is not a 'security' feature, but still request the ability to limit to certain MAC's.

What are some alternative options for when we exceed 256 devices in the filter?

Above 256, you would likely be exceeding the intended scope of the feature in
HiveOS/HiveManager. I don't think HiveManager would be suited to the lifecycle/management overheads of maintaining MAC address
lists that are larger.

To go further, I expect it is intended that you would use a third party RADIUS server such as NPS, FreeRADIUS or RADIATOR where there isn't such a limit and systems can be put in place to manage and work with large sets of MAC addresses.

For 802.1X, you get the client's MAC address in the Calling-Station-Id attribute of the Access-Request packets as EAP authentication takes place.(The Service-Type attribute will have a value of Framed for 802.1X.)

If there is a perceived need, you can also use dedicated MAC address authentication and use the same attribute in the Access-Request packets, 'useful' for Open and PSK/PPSK protected SSIDs.(The Service-Type attribute will have a value of Call-Check for dedicated MAC auth.)